Visual symptoms often accompany pituitary diseases. Pituitary tumors may compress surrounding structures such as optic chiasm leading to visual field defects including bitemporal hemianopia and visual disturbance. They also may compress cranial nerves III, IV, and VI, leading to ocular motility abnormalities. Pituitary adenomas are the most common cause of chiasmal compression. Patients with nonsecreting tumors present initially with vision loss, and these tumors can reach large size without causing other symptoms; however, hormonally active tumors are detected before vision loss because of systemic symptoms. Acute hemorrhage or infarction of the pituitary tumor known as pituitary apoplexy causes diplopia, loss of vision, and visual field. Thus, the ophthalmologist’s role is crucial in diagnosis and treatment of pituitary tumors. As visual loss may be the first sign of recurrence after treatment, it is essential to repeat visual field and visual acuity testing every 6–12 months.
Part of the book: Pituitary Diseases